Research On Tolerance Allocation Of Coordination Points Oriented To Aircraft Fuselage Assembly

Fuselage assembly is an important part of aircraft final assembly, among which the coordinationof the overall fuselage shape is the guarantee to the quality of aerodynamics, assembly accuracy andstructural strength. In current days, national aircraft plants use laser collimators to aim the positioningfeatures, thus to judge whether the fuselage bodies are accurately assembled. The method is of lowefficiency and, to much extent, relies on experience of workers, therefore it is weak in applying toaircraft manufacture. Since that, the research on tolerance allocation of the coordinating points islaunched on the requirement of domestic aeronautics industry to transfer digital quantity in theprocess of fuselage assembly and profile coordination. The main research in the thesis is as follows:1) Based on the research of profile coordination of aircraft fuselage assembly, a study on themethod of profile coordination through coordinating points is committed. The realization of themethod consists of the construction of fuselage assembly coordination model as well as the theory offuselage coordination, the principles to define the coordinating points, and the analysis of the errortransmission route of the points’coordinates.2) According to relative position of coordinating points and the fuselages to be coordinated, atolerance model of coordinating points is designed; on the research of the homogeneous coordinatetransformation for error computation, a series of axis systems and the coordinate error chain areestablished; furthermore the expression and calculation method are provided.3) Concrete procedures for the allocation of the coordinating points’ tolerance are listed. Giventhe accuracy of parameters for estimating fuselage assembly profile coordination, pose-and-positionparameters are firstly allocated, and secondly the tolerance of coordinating point coordinates isallocated on each fuselage; based on the above, the analysis of fuselage assembly profile coordinationis preceded, including axis angle between fuselages and the degree of symmetry of the assembledfuselage as a whole.4) A software of tolerance allocation for the coordination points in fuselage assembly isdeveloped, including the software frame establishment and functions design. It is applied to the caseof mid-fuselage and fore-fuselage assembly of some domestic regional jet, and the outcome isanalyzed in the last.